import io.reactivex.Observable;

public class C23b {
    public static void main(String[] args) {
        Observable.just("Alpha", "Beta", "Zeta", "Eta", "Gamma", "Delta")
                  .distinctUntilChanged(String::length)
                  .subscribe(i -> System.out.println("RECEIVED: " + i));
    }

}
//EOP
